SkyLock 800 Blocks - SWL 800Kg (1760lbs) The Barton Marine SkyLock Blocks feature 316 stainless steel side plates, glass reinforced nylon cover plates and internal self-locking aluminium cam to lift and lock loads securely. The clever design and construction of the locking cams means the control line will never allow loads to drop even when accidentally released. Designed for use in conjunction with 3:1 or 4:1 purchase systems. Can be used for commercial and leisure marine operations including a davit hoist system to lift dinghies, outboards, provisions and equipment on board, especially useful when short handed. Part of the Barton range